Method of fabricating node contacts

Abstract

A method of fabricating a node contact on a substrate, which contains a first conductive device and an insulating layer covering the substrate and the first conductive device, includes forming at least two conductive lines on the insulating layer, wherein the conductive lines are separated by a first distance; forming at least two second conductive devices on the insulating layer, wherein the second conductive devices are separated by a second distance, and wherein one of the conductive lines and one of the second conductive devices are separated by a third distance, and wherein both the first and second distances are greater than the third distance; forming an isolation layer of a thickness on the substrate to cover the insulating layer, the conductive lines and the second conductive devices, wherein the isolation layer comprises a dished area located between the second conductive devices; removing a portion of the isolation layer to form a spacer around the second conductive devices, and to deepen the dished area to form an opening exposing the insulating layer; deepening the opening to expose the first conductive device; and filling the opening with a conductive material.

What is claimed is:  
     
       1. A method of fabricating a node contact on a substrate, wherein the substrate comprises a first conductive device and an insulating layer covering the substrate and the first conductive device, the method comprising steps of: 
       forming at least two conductive lines on the insulating layer, wherein the conductive lines are separated by a first distance;  
       forming at least two second conductive devices on the insulating layer, wherein the second conductive devices are separated by a second distance, and wherein one of the conductive lines and one of the second conductive devices are separated by a third distance, and wherein both the first and second distances are greater than the third distance;  
       forming an isolation layer of a thickness on the substrate to cover the insulating layer, the conductive lines and the second conductive devices, wherein the isolation layer comprises a dished area which is located between the second conductive devices;  
       removing a portion of the isolation layer to form a spacer around the second conductive devices, and to deepen the dished area to form an opening exposing the insulating layer;  
       deepening the opening to expose the first conductive device; and  
       filling the opening with a conductive material.  
     
     
       2. The method of  claim 1 , wherein the isolation layer includes silicon nitride. 
     
     
       3. The method of  claim 2 , wherein the step of forming an isolation layer includes chemical vapor deposition. 
     
     
       4. The method of  claim 2 , wherein the step of removing a portion of the isolation layer includes dry etching. 
     
     
       5. The method of  claim 1 , wherein the thickness is greater than one half of the third distance. 
     
     
       6. The method of  claim 1 , wherein the conductive material includes polysilicon. 
     
     
       7. The method of  claim 6 , wherein the step of filling the opening includes chemical vapor deposition. 
     
     
       8. The method of  claim 1 , wherein the conductive lines include metal silicide. 
     
     
       9. The method of  claim 1 , wherein the second conductive devices include metal silicide. 
     
     
       10. A method of fabricating a node contact on a substrate, wherein the substrate comprises a first conductive device and an insulating layer covering the substrate and the conductive device, the method comprising steps of: 
       forming a first conductive line and a second conductive line on the insulating layer, wherein the first and second conductive lines are separated by a first distance;  
       forming on the insulating layer, a second conductive device connected to the first conductive line and a third conductive device connected to the second conductive line, wherein the second and third conductive devices are separated by a second distance, and wherein the second conductive device and the second conductive line are separated by a third distance, and wherein the first and second distances are greater than the third distance;  
       forming an isolation layer of a thickness on the substrate to cover the first insulating layer, the first and second conductive lines, and the second and third conductive devices, wherein the isolation layer comprises a dished area between the second and third conductive devices;  
       removing a portion of the isolation layer to form a spacer around the second and third conductive devices, and to deepen the dished area to form an opening exposing the first insulating layer;  
       deepening the opening to expose the first conductive device; and  
       filling the opening with a conductive material.  
     
     
       11. The method of  claim 10 , wherein the isolation layer includes silicon nitride. 
     
     
       12. The method of  claim 11 , wherein the step of forming an isolation layer includes chemical vapor deposition. 
     
     
       13. The method of  claim 11 , wherein the step of removing a portion of the isolation layer includes dry etching. 
     
     
       14. The method of  claim 10 , wherein the thickness is greater than one half of the third distance. 
     
     
       15. The method of  claim 10 , wherein the conductive material includes polysilicon. 
     
     
       16. The method of  claim 15 , wherein the step of filling the opening includes chemical vapor deposition. 
     
     
       17. The method of  claim 10 , wherein the first and second conductive lines include metal silicide. 
     
     
       18. The method of  claim 10 , wherein the second and third conductive devices include metal silicide.